Gateway system, gateway system configuring method, and gateway apparatus

ABSTRACT

To provide a gateway system capable of handling more gateways in one gatekeeper by dividing gatekeeper functions and mounting a part of the H.323 gatekeeper functions in a gateway apparatus. The gateway apparatus includes a proxy gatekeeper, and a gateway. A master gatekeeper and the gateway apparatus form an H.323 zone, and communicate with gatekeepers and endpoints in other zones via a network address &amp; port number translator.

This application is a continuation of application Ser. No. 09/604,879,filed Jun. 28, 2000, now pending.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a gateway system, gateway systemconfiguring method, and a gateway apparatus in an H.323 specificationcommunication system, especially to the gateway system, it's configuringmethod, and a gateway apparatus which is capable of handling moregateways in one gatekeeper by dividing H.323 gatekeeper functions andmounting part of the gatekeeper functions, in each gateway apparatus.

2. Description of the Prior Art

Up to now, H.323 gateway systems have been used for relay betweencommunication conforming to ITU-T recommendation H.323, which is astandard specification of a service quality non-guaranteed LAN andcommunication conforming to another standard different from therecommendation H.323 so as to perform protocol conversion. In an H.323model, one zone is configured by one gatekeeper, and one or moreendpoint(s) (gateway(s) or H323 terminal(s)). The gatekeeper performsaddress translation, access conversion control, bandwidth management, orthe like, and controls the gateway(s). If a number of gateways in onezone increases, convergence of gatekeeper processing is avoided byproviding a plurality of gatekeepers. Nevertheless, since a gateway canbe registered in only one gatekeeper at the same time, gateways areseparated into a plurality of zones configured every gatekeeper.

BRIEF SUMMARY OF THE INVENTION Object of the Invention

Nevertheless, the conventional technology described above has followingproblems.

A first problem is that, if a plurality of zones is configuration in astate of a number of gateways being not changed, a call loss probabilitybecomes large. This is because, the smaller the scale of one zonebecomes, the smaller a mass effect becomes. On the contrary, so as tokeep a call loss probability, a number of gateways increasesreluctantly.

A second problem is that, in the case of one-zone configuration, anumber of gateways that can be contained is limited by the capacity of agatekeeper. In order to contain more gateways in one zone, it isnecessary to use a higher-performance gatekeeper.

The present invention is to provide a gateway system and gateway systemconfiguring method for solving the above-described problems, the gatewaysystem which handles more gateways in one gatekeeper by dividinggatekeeper functions in an H.323 specification communication system andmounting part of the gatekeeper functions in a gateway apparatus.

SUMMARY OF THE INVENTION

In order to solve the above-described problems, a gateway system, it'sconfiguring method and a gateway apparatus according to the presentinvention in an H.323 specification communication system ischaracterized in that the gateway system comprises a master gatekeeperhaving a gateway control function including an address translationfunction for communicating with other zones, a zone management function,and a call control signaling-function, a proxy gatekeeper having theaddress translation function and zone management function out of thegateway control function of this master gatekeeper, and a gatewayperforming protocol conversion for communicating with other zones.

Owing to the above configuration, the gateway system handles an addresstranslation request in the proxy gatekeeper to reduce the load of themaster gatekeeper.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other objects, features and advantages of thisinvention will become more apparent by reference to the followingdetailed description of the invention taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a block diagram of a gateway system according to the presentinvention;

FIG. 2 is a functional block diagram of an H.323 gatekeeper;

FIG. 3 is an explanatory diagram of transmission and reception between agateway and an endpoint;

FIG. 4 is another explanatory diagram of transmission and receptionbetween a gateway and an endpoint;

FIG. 5 is a functional block diagram of another H.323 gatekeeper;

FIG. 6 is still another explanatory diagram of transmission andreception between a gateway and an endpoint; and

FIG. 7 is a further explanatory diagram of transmission and receptionbetween a gateway and an endpoint.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Next, embodiments of the present invention will be described withreference to drawings.

FIG. 1 shows a configuration of the present invention, and thisembodiment includes a master gatekeeper 1, a gateway apparatus 2, and anetwork address & port number translator 3. The gateway apparatus 2comprises a proxy gatekeeper 21, and a gateway 22. The master gatekeeper1 and gateway apparatus 2 forms a zone 6 described in the H.323specification, and the zone 6 communicates with a gatekeeper 4 and anendpoint 5 in another zone 7 via the network address & port numbertranslator 3.

The gateway apparatus 2 comprises the H.323 gateway 22 and proxygatekeeper 21. The proxy gatekeeper 21 has an address translationfunction and a zone management function that are similar to those of themaster gatekeeper 1. The H.323 gateway 22 performs protocol conversionfor the communication of the H.323 zone 6 with another zone 7.

As shown in FIG. 2, the functions of a conventional H.323 gatekeeper 8is functionally dispersed in the master gatekeeper 1 and proxygatekeeper 21. The proxy gatekeeper 21 has an address translationfunction 21 a and a zone management function 21 b out of the gatewaycontrol function that the conventional H.323 gatekeeper 8 has forprocessing, so as to resolve a bottleneck due to access convergence fromgateways. The master gatekeeper 1 has an admission control function 1 e,a bandwidth control function id, a call control signaling-function 1 e,a call authorization function 1 f, a band width management function 1 g,and a call management function 1 h besides an address translationfunction 1 a and a zone management function 1 b.

The network address & port number translator 3 has a function formutually translator network addresses and port numbers when any one ofthe master gatekeeper 1, proxy gatekeeper 21, and gateway 22communicates with another zone 7. A port number is an address in atransport layer. In particular, by translator a network address and aport number of the master gatekeeper 1 into a network address and a portnumber of the proxy gatekeeper 21, the proxy gatekeeper 21 seems fromthe gatekeeper 4 and endpoint 5 of another zone 7 to be a gatekeeper ofthe zone 6 instead of the master gatekeeper 1.

The gateway 22 has a function for anew requesting an admissions requestto a call, whose participation is negated by the proxy gatekeeper 21, ofthe master gatekeeper 1 in addition to the conventional H.323 gatewayfunction.

Next, the operation of this embodiment will be described with referenceto FIGS. 1, 3, and 4 in detail.

In FIG. 3, when transmitting a signal to the endpoint 5, the gateway 22transmits an admissions request A1 to the proxy gatekeeper 21. The proxygatekeeper 21 transmits location request A2 to the gatekeeper 4 ofanother zone 7 by the address translation function, and acquires atransport address for signaling the endpoint 5 from the response oflocation confirm A3. The proxy gatekeeper 21 transmits admission confirmA4 to the gateway 22 if acknowledging the admission request A1. Thegateway 22 opens a signaling channel A5 to a transport addressdesignated in the admission confirm A4.

On the other hand, in FIG. 4, if the gateway 22 transmits an admissionsrequest B1, requesting a function that the proxy gatekeeper 21 does nothave, the proxy gatekeeper 21 transmits admission reject B4. The gateway22 receiving the admission reject B4 transmits an admissions request B5to the master gatekeeper 1. The master gatekeeper 1 transmits anadmissions confirm B6 to the gateway 22 if acknowledging the admissionrequest. The gateway 22 opens a signaling channel B7 to a transportaddress designated in the admission confirm B6.

Next, the operation of this embodiment will be described by using aconcrete example. For example, in FIG. 3, if transmitting a signal to analias address of the endpoint 5, “012-345-6789”, the gateway 22 firsttransmits the admission request A1, sent to this alias address“012-345-6789”, to the proxy gatekeeper 21. The proxy gatekeeper 21transmits the location request A2 to the gatekeeper 4 containing thisalias address of the endpoint 5, “012-345-6789”, and acquires atransport address “10.1.2.3:1720” for the endpoint 5 from the responseof the location confirm A3. After that, the proxy gatekeeper 21transmits the admission confirm A4, including the transport address“10.1.2.3:1720” for the endpoint 5, to the gateway 22. The gateway 22opens the signaling channel A5 to the transport address “10.1.2.3:1720”designated.

In addition, in FIG. 4, if transmitting the admission request B1,including user authentication, to the proxy gatekeeper 21, the proxygatekeeper 21 transmits the admission reject B4 since not having aauthentication function. The gateway 22 receiving the admission rejectanew transmits the admission request B5 to the master gatekeeper 1. Themaster gatekeeper 1 transmits the admission confirm B6 to the gateway 22if the user authentication is successful and the master gatekeeper 1acknowledges the admission request. The gateway 22 opens the signalingchannel B7 to a transport address designated in the admission confirmB6.

Next, another embodiment of the present invention will be described.

In FIG. 5, this embodiment is different at the point of having a callcontrol signaling-function 21 e in addition to the address translationfunction 21 a and zone management function 21 b in the embodiment shownin FIG. 2. Owing to that, a signaling channel between the gateway 22 andendpoint 5 is not directly opened by the judgment of the proxygatekeeper 21 as shown in FIG. 6. Nevertheless, a signaling channel C5between the gateway 22 and proxy gatekeeper 21 and a signaling channelC6 between the proxy gatekeeper 21 and endpoint 5 are opened.

In addition, with referring to FIG. 7, this embodiment is different atthe point of giving the information of a transport address for signalingthe master gatekeeper 1 instead of the transport address for signalingthe endpoint 5, in admission confirm D6 the information of which themaster gatekeeper 1 gives to the gateway 22. Owing to this, thesignaling channel between the gateway 22 and endpoint 5 is not directlyopened. Nevertheless, a signaling channel D7 between the gateway 22 andmaster gatekeeper 1 and a signaling channel D8 between the mastergatekeeper 1 and endpoint 5 are opened.

The network address & port number translator 3 mutually translator anetwork address and a port number of the master gatekeeper 1 and anetwork address and a port number of the proxy gatekeeper 21 every timea signal transmitted or received on the signaling channel D8 passes thenetwork address & port number translator 3. In consequence, thesignaling channel D8 seems from the endpoint 5 to be a signaling channelD9 opened between the endpoint 5 and proxy gatekeeper 21.

Next, a concrete example will be described. For example, in FIG. 6, ifthe gateway 22 transmits a signal to an alias address of the endpoint 5,“012-345-6789”, the gateway 22 first transmits an admissions request C1,requesting the participation in this alias address “012-345-6789”, tothe proxy gatekeeper 21. The proxy gatekeeper 21 transmits locationrequest C2 to the gatekeeper 4, containing this alias address of theendpoint 5, “012-345-6789”, to acquire a transport address of theendpoint 5, “10.1.2.3:1720” from the response of location confirm C3.After that, the proxy gatekeeper 21 transmits admission confirm C4,including the transport address “10.1.2.3:1720” of the proxy gatekeeperitself instead of the transport address for the endpoint 5, to thegateway 22. The gateway 22 opens the signaling channel C5 to thetransport address “10.1.2.3:1720” designated.

Furthermore, the proxy gatekeeper 21 opens the signaling channel C6 tothe transport address “10.1.2.3:1720” for the endpoint 5. The signalingchannels C5 and C6 forms a signaling channel between the gateway 22 andendpoint 5.

In addition, in FIG. 7, if the gateway 22 transmits a signal to thealias address of the endpoint 5, “012-345-6789”, procedure from anadmissions request D1 to an admissions request D5 is similar to theprocedure from the admission request B1 to the admission request B5 inFIG. 4. The master gatekeeper 1 transmits an admission confirm D6,including the transport address of the master gatekeeper 1 itself,“10.1.2.3:1720” instead of the transport address for the endpoint 5,“10.1.2.3:1720”, to the gateway 22 at the step of the admission confirmD6. The gateway 22 opens the signaling channel D7 to the transportaddress “10.4.5.7:1720” designated. Furthermore, the master gatekeeper 1opens a signaling channel D8 to the transport address of the endpoint 5,“10.1.2.3:1720”. The signaling channels D7 and D8 forms a signalingchannel between the gateway 22 and endpoint 5.

Here, the network address & port number translator 3 mutually translatora network address and a port number of the master gatekeeper 1, whichare included in a signal sent from the master gatekeeper 1 to theendpoint 5, into a network address and a port number of the proxygatekeeper 21 when the network address and port number of the mastergatekeeper 1 pass the network address & port number translator 3. On thecontrary, the network address & port number translator 3 mutuallytranslator a network address and a port number of the proxy gatekeeper21, which are included in a signal sent from the endpoint 5 to themaster gatekeeper 1, into a network address and a port number of themaster gatekeeper 1 when the network address and port number of theproxy gatekeeper 21 pass the network address & port number translator 3.Therefore, the signaling channel D8 seems from the endpoint 5 to be thesignaling channel D9 opened between the endpoint 5 and proxy gatekeeper21.

As described above, if transmitting a signal to the endpoint 5, thegateway 22 performs an admissions request, requesting the participationto the H.323 communication, to the proxy gatekeeper 21. The proxygatekeeper 21 acquires an addressee's address of the endpoint 5 by theaddress translation function. Then, the proxy gatekeeper 21 gives theinformation, including the addressee's address in admission confirm, tothe gateway 22 if admission the admission request. If not, the proxygatekeeper 21 informs the gateway 22 of admission reject, including theaddressee's address.

The gateway 22 anew performs an admissions request, requesting theparticipation in the H.323 communication, to the master gatekeeper 1 ifthe participation is negatively acknowledged. The master gatekeeper 1judges whether the admission request of the gateway 22 is admission.Then, the master gatekeeper 1 informs the gateway 22 of the admissionconfirm or admission reject. After receiving the admission confirm fromthe proxy gatekeeper 21 or master gatekeeper 1, the gateway 22 opens asignaling channel between the gateway 22 and endpoint 5 to perform thesubsequent H.323 procedure.

Owing to this, it becomes possible to handle more gateways than gatewaysthat one conventional gatekeeper can handle.

As described above, the present invention handles an address translationrequest of a gateway with a proxy gatekeeper inside a gateway apparatusto reduce the load of a master gatekeeper. Therefore, it is possible tohandle more gateways than gateways that one conventional gatekeeper canhandle. In consequence, it becomes unnecessary to increase theprocessing capability of a gatekeeper or add a gatekeeper as a number ofgateways is increased.

In addition, it is possible to reduce the processing wait time of agateway, which is necessary only for address translation, by processingan address translation request of a gateway with a proxy gatekeeperinside a gateway apparatus.

1. A gateway system which handles more gateways in one gatekeeper bydividing the gatekeeper functions into each gateway apparatus as a proxygatekeeper which has the address translation function and zonemanagement function.
 2. A gateway system in an H.323 specificationcommunication system, comprising: a master gatekeeper having a gatewaycontrol function including an address translation function forcommunicating with other zones, a zone management function, and a callcontrol signaling-function; a proxy gatekeeper having the addresstranslation function and zone management function out of the gatewaycontrol function of this master gatekeeper; and a gateway performingprotocol conversion for communicating with other zones.
 3. The gatewaysystem according to claim 2, wherein the proxy gatekeeper has a callcontrol signaling-function.
 4. The gateway system according to claim 3,wherein the proxy gatekeeper and the gateway are contained in anidentical apparatus.
 5. The gateway system according to claims 4,wherein the gateway transmits an admissions request to the mastergatekeeper when receiving admission reject to transmission of anadmissions request to the proxy gatekeeper.
 6. The gateway systemaccording to claim 2, wherein the gateway system has a network address &port number translator mutually translate network addresses and portnumbers when any one of the master gatekeeper, the proxy gatekeeper, andthe gateway communicates with other zones.
 7. The gateway systemaccording to claim 6, wherein the master gatekeeper informs the gatewayof a transport address for signaling the master gatekeeper, and thenetwork address & port number translator mutually translator a networkaddress and a port number of the master gatekeeper and a network addressand a port number of the proxy gatekeeper when the master gatekeepercommunicates with other zones.
 8. The gateway system according to claim2, the gateway transmits an admissions request to the proxy gatekeeperto transmit a signal to a endpoint in other zones, wherein the proxygatekeeper transmits location request to the gatekeeper of other zonesby the address translation function, and acquires a transport addressfor signaling the endpoint from the response of location confirm
 9. Thegateway system according to claim 8, wherein said proxy gatekeepertransmits admission confirm to the gateway if acknowledging theadmission request, and said gateway opens a signaling channel to atransport address designated in the admission confirm
 10. A method ofconfiguring a gateway system for handling more gateways in onegatekeeper comprising the steps of: dividing the gatekeeper functionsinto each gateway apparatus as a proxy gatekeeper; and addresstranslating when any one of a master gatekeeper, the proxy gatekeeper,and the gateway communicates with other zones.
 11. A method ofconfiguring a gateway system in an H.323 specification communicationsystem comprising the steps of: centralized gateway controlling by amaster gatekeeper including an address translation for communicatingwith other zones, a zone management, and a call control signaling;distributed gateway controlling by a proxy gatekeeper including addresstranslation and zone management out of the gateway controlling of thismaster gatekeeper; and protocol converting by a gateway forcommunicating with other zones.
 12. A method of configuring a gatewaysystem according to claim 11, comprising the steps of: firsttransmitting an admissions request from the gateway to the proxygatekeeper; and second transmitting an admissions request from thegateway to the master gatekeeper when receiving an admissions reject totransmission from said proxy gatekeeper.
 13. A method of configuring agateway system according to claim 12, comprising the step of translatingnetwork addresses and port numbers mutually when any one of the mastergatekeeper, the proxy gatekeeper, and the gateway communicates withother zones.
 14. A method of configuring a gateway system according toclaim 13, comprising the steps of: informing the gateway of a transportaddress for signaling the master gatekeeper, and translating a networkaddress and a port number of the master gatekeeper and that of the proxygatekeeper mutually when the master gatekeeper communicates with otherzones.
 15. A method of configuring a gateway system according to claim14, comprising the steps of: transmitting an admissions request by thegateway to the proxy gatekeeper to transmit a signal to a endpoint inother zones; and transmitting a location request by the proxy gatekeeperto the gatekeeper of other zones to acquire a transport address forsignaling the endpoint from the response of location confirm
 16. Amethod of configuring a gateway system according to claim 15, comprisingthe steps of: transmitting admission confirm said proxy gatekeeper tothe gateway when acknowledging the admission request; and opening asignaling channel by the gateway to a transport address designated inthe admission confirm.
 17. A gateway apparatus in an H.323 specificationcommunication system including a proxy gatekeeper which has the addresstranslation function and zone management function.
 18. A gatewayapparatus according to claim 17, comprising: a proxy gatekeeper havingthe address translation function and zone management function out of thegateway control function of this master gatekeeper; and a gatewayperforming protocol conversion for communicating with other zones.
 19. Agateway apparatus according to claim 18, wherein the proxy gatekeeperhas a call control signaling-function.
 20. A gateway apparatus accordingto claim 19, further comprising a transmitting part to transmit anadmissions request to the master gatekeeper when receiving admissionreject to transmission of an admissions request to the proxy gatekeeper.